In the past, machined tubular metal castings have been used to connect the exhaust pipe of a muffler with the outlet of a turbocharger. The machined casting has a relatively thin wall, and the ends of the casting are provided with circumferential flanges which are adapted to engage the inner walls of the muffler exhaust pipe and the turbocharger outlet pipe, respectively.
As the connector has a relatively thin wall, it is difficult to maintain the outer diameter of the flanges within precise tolerances and due to the required machining, the connector is extremely expensive to manufacture.